low rolling resistance tyre

[D.O.G.]

Originally Posted by jkv357

Keep in-mind that a motorcycle wheel is not designed to take the lateral loads like an auto wheel. Using a motorcycle wheel on the front of a 4-wheel vehicle may cause it to fail.

I've owned two motorcycle & sidecar outfits, a Honda GoldWing and a vintage Norton, both with standard spoked rims.
Neither had any issue with ordinary motorcycle tyres on the front, apart from a bit of scrubbing during hard cornering.

Triplerotor, have you looked at the availability of flat tread motorcycle tyres, like the Avon triple duty sidecar tyre.
I think the Avons only come in 19", but other manufacturers may stock smaller ones.
I once used a flat tread 16" tyre on the rear of my GoldWing, but that was many years ago and I no longer remember what brand that was.

[jkv357]

Originally Posted by D.O.G.

I've owned two motorcycle & sidecar outfits, a Honda GoldWing and a vintage Norton, both with standard spoked rims.
Neither had any issue with ordinary motorcycle tyres on the front, apart from a bit of scrubbing during hard cornering.

Nowhere near the same lateral loads on the wheels in a sidecar configuration vs running them on the front of a 4-wheel vehicle.

[RunningOnEmpty]

Go to the Shell Eco-marathon web site and search. You can buy special Michelin low rolling resistance tires for both the Urban concept and the regular prototype classes through Shell.

About the tires

Michelin Tires

Teams are not required to use Michelin tires and are free to use tires of their choosing. Please ensure that the tires properly fit the wheel. Below are the available options:

Michelin 44-406 Prototype tires (view photo) = $79 USD

The specs for these tires are 44-406 (20" x 1.75"); inflate up to 50PSI
Download the technical specifications of the Michelin conventional tires
Rolling resistance: 2 kg/t (Kilogramme/tonne)

Michelin UrbanConcept tires (view photo) = $235 USD

Download the technical specifications for the Michelin UrbanConcept tires
Rolling resistance: 95/80 R 16: 1.5 kg/t

Michelin Radial 45-75 R16 tires (view photo) = $235 USD

Download the technical specifications for the Michelin Radial tires

Due to limited supply, we are only able to provide a reasonable number of tires to registered Shell Eco-marathon Americas participants.

To order tires, please contact your Relationship Manager or send an email to ecomarathonamericas at shell.com. VISA, MasterCard, AMEX and Discover Card are accepted. You will need to provide the following information: Desired quantity, credit card number, expiration date, security Code, shipping address and billing zip code.

I've mentored a Eco marathon HS team for 3 years now. These tires are about as good as you are going to find as regular motorcycle tires aren't being marketed for fuel economy gains just yet..

good luck

[triplerotor]

Originally Posted by RunningOnEmpty

Go to the Shell Eco-marathon web site and search. You can buy special Michelin low rolling resistance tires for both the Urban concept and the regular prototype classes through Shell.

good luck

thanks! i guess the best way is to source for funding to get the tyres.

anyway,as im using scooter engine can i use coast and glide method? the motor did have an electric starter. does running the starter for a few times got any effects?

[sendler]

Are you using the scooter cvt? They can't really puls n glide.

[RunningOnEmpty]

I've mentored a Formula SAE team, a IGVC Robotic team and a Shell Eco-Marathon team.
I've seen students make the same mistakes repeated over and over. I could write a book on the subject of school STEM competitions, but the most frustrating thing is students often don't listen to expert advice, think the internet has all the answers and never, ever allow enough time to get ready for the event.

Every team gets 12 months from the completion of the last event.
The event is in February so if you are just now making plans you are already 1/2 year behind.

This is a difficult event and not easily done effectively on a budget. It's hard enough to build a vehicle that passes Shell's technical inspection, hard to build a scratch built vehicle that won't fail, even harder still to be remotely competitive. I don't want to make any presumptions, but I can tell by your postings this is going to be a struggle. If you are doing this yourself, you may want to join an established team and learn all you can before investing money in a competition car.

It's not just money. I've seen big name, well funded university teams fail in a big way because they got too enamored with expensive high tech (Carbon Fiber!) but couldn't get the unglamorous mechanical basics to work.

It looks like from the the posted Shell Asia 2015 results there were 120 teams from 17 countries entered. Not sure how many were DNF or DNS.
The 11 finishers in the prototype gasoline fuel class ranged from 75.3 km/L (176 mpg) to 1480 km/L (3,481 mpg). Tough competition and very similar to results here in America.
Added: The Urban Concept 4 wheelers were 52 km/l (122 mpg) to 127 km/l (176 mpg) but have more stringent rules (Seats, wipers, lights, ability to run in the rain, must come to a complete stop every lap on the course.) Hopefully you have downloaded the rules and studied them. Note the required glass fuel bottle is as pricey as the tires.


If any of this dissuades you then you would have failed anyway. If you decide to forge ahead, then good luck and start sooner next time.

[triplerotor]

Its good to have someone experienced in sem here. I understand its a highly technical comp and i know most participants mostly didnt really care about the unglamorous technical subject. as the previous team have failed last event. even the lecturer tells us most of the work have been done by him not the students. and we have pin pointed the problem and were actually being really anal about the fabrication. lol. i myself, as a car enthusiast understands the important of the technical view point as this is mostly where people ignore as they tend to focus on the glamourous part of it.
Actually We have planned everything including the simulation,design. We have passed staged 1 and on stage 2 now. currently were in the process of fabricating and awaiting the budget and materials to arrive. my point to ask questions here just to double confirm our choice and maybe there are some aspect that were missed.

we opted simple design and used parts that are from bikes,gokart to reduce the timeload rather than fabricating the gearbox ourselves.

for the chassis,we have opted aluminium 6063 tubing. and the steering mostly we refer tp the gokart steering design. theyre more detail about that but ill maybe share it somewhere else as this is ecomodder tyre topic. lol

btw, is there anywhere to contact you. as i have some other questions related to sem. fb email or anything. you can pm me if you want.

[RunningOnEmpty]

I sent you a PM with my email and answers to some questions. I fully understand your advisers frustrations having to build most of parts the students didn't or couldn't get done.
Again many, many 1st time teams around the world woefully underestimate the difficulty of this event and time required. I walk around the pits and see teams still building their cars on the 1st day of the competition and you'll see many still struggling on the last day.

If you make it to the event you'll be much wiser once you see the other cars and see how the event is run.
Your strategy to collect existing parts and put them together may sound like the easy and cheap route but it's frequently not. The team that I got snared to mentoring had thought it would be easy to just get a recumbent bike and throw a motor on it and go to the races. That turned out to be a bad idea for a number of reasons. Steering geometry was inefficient and wasted power on turns, Bicycle parts weren't up to the torque and abuse of start stop cycles, drive chain kept tossing, break and fix, on and on it went.
By the time the car was completed there was little left of the original. The parts that worked the best were the bespoke parts designed specifically for the event.

Car needs to be able to complete all the laps without breaking. Design for robustness and serviceability. You only get a few chances to run and if you break something on your first run you may only have a few hours to fix it before your next or last chance.

Car needs to be able to coast a long way engine off with little energy loss. Good wheel bearings are critical. Chassis design is important to fuel efficiency. A flexible chassis eats energy as it twists back and forth. The students designed and built a super light aluminum frame but didn't follow my advice on triangulation and torsional rigidity. First time on the floor it was so flexy it clearly wasn't viable. Required additional bracing which made it heavier than if it was designed correctly in the first place.
Tires are the easy part. Just get the blue Michelins. Everybody uses them because they are the best and specifically designed for this event.
good luck

[Vekke]

Some good information in this study:
https://publications.lib.chalmers.se...040/200040.pdf